This invention relates generally to the field of measuring, and in particular to variability measurements. More specifically, the invention relates to measuring the extent of curvature or warpage found in stacked materials.
A wide variety of equipment is used to process various materials, such as paper sheets, envelopes, and the like. Examples of such equipment include copiers, printers, fax machines, mail processing equipment, and the like. Such equipment often uses a stack of materials to increase the efficiency of the process. For instance, mail processing equipment often utilizes a stack of envelopes or inserts into the envelopes when preparing mailings. As one specific example, an insert may be grasped from a stack and placed onto other materials that are to be inserted into an envelope. In turn, the envelope may also be grasped from a stack before receiving the materials.
In some cases, the materials may be curved or warped. As such, they may be difficult to grasp or move from the stack. This may cause a miss or a misfeed that may in turn stop operation of the equipment.
Hence, this invention is related to ways to measure variability in a stack of materials. Such measurements may then be used to determine if such materials are acceptable for certain equipment.
The invention provides various systems and methods for measuring the variability along the surface of materials that are stacked on top of each other. One such system and method comprises a holder having a base and at least two sides that extend upward from the base. With this configuration, a stack of materials may be placed onto the base and then positioned to be flush against the two sides. The system further includes a measuring device to measure the distance between a top of the stack of materials and a plane that is fixed relative to the base measurements are made at various locations along the top of the stack and these measurements are used to determine the height variability along the top of the stack. If the variability is too great, the materials may be rejected as being non-compliant and/or reworked until acceptable for use with the desired machine.
The fixed plane may be defined by the base so that the height measurements are made relative to the base. Markers may be placed along the walls so that visual measurements may be taken. Alternatively, the holder may include a top or a lid that is attached to the walls and is parallel to the base. In this way, the measurements may be taken relative to the lid. For example, the lid may include a plurality of holes through which a measuring device may be placed. For example, calipers may be placed through the holes and used to make the measurements. The two walls may be perpendicular to each other to define a corner into which a corner of the stack of materials may be inserted. Measurements may then be taken along x and y axis that are parallel to the two walls.
The systems and methods may be used to measure a wide variety of materials. For example, the materials may comprise envelopes, paper sheets, cardstock and the like.
The variability may be calculated manually or by a processor. For example, the measuring device may make electronic measurements that are transmitted to a processor that is configured to calculate the variability. Further the variability calculations may be made for various locations along the top of the stack of materials.